This invention relates to heat exchanger units for central air conditioning systems, heat pumps and the like. More particularly this invention relates to cabinets for such heat exchanger units and specifically to louvred tops therefor.
Central air conditioning or heat pump systems for residential and light commercial use generally employ a condenser unit located outside and an evaporator unit located inside the space whose temperature is to controlled. The condenser unit includes a compressor, a heat exchanger, appropriate valves and piping, and a fan and electric motor for driving the fan to move air over the heat exchanger. Typically, these components are housed in a cabinet having an apertured top through which the fan expels air out of the cabinet after it is drawn into the cabinet and is blown over the heat exchanger.
It is very important for the proper operation of an air conditioning or heat pump system that heat be efficiently transferred by the heat exchanger located in the condenser unit. Thus, it is very important for the proper operation of the system that the apertured top of the condenser housing permits air to flow out of the cabinet in sufficient quantities and with negligible pressure loss. Further, it is important in these types of systems that, during shipment from the factory to the residence, the units not be damaged and that the alignment of the fan with the air inlet opening in the top of the cabinet be properly maintained.
The cabinet tops or covers for prior art air conditioning condenser units have typically included an aperture which was covered by a wire or plastic grille to meet industry standards and agency requirements. Further, these arrangements prevent debris such as leaves, twigs and the like from entering the cabinet and causing damage to the internal structure of the unit. However, removal of material to form an aperture in the cover of such prior art units and disposing of such removed material was wasteful. It is therefore desired to eliminate the need for removing material in forming cabinet tops.
Another problem with prior art cabinet arrangements has been the mounting of the motor. In several prior art arrangements, the motor mounting bracket has been secured directly to the cabinet top. However, these prior art arrangements have not been satisfactory as the motor mounting arrangements were rather complicated and expensive and furthermore caused undue vibration which was transmitted to the cabinet, thereby causing undesirable noise and potential loosening of fasteners, etc.
Some prior art condenser tops have been provided which have been formed from a single sheet of material such as cold rolled steel. However, in these systems, the size of the top is limited due to the inherent flexibility of the material and due to the fact that by providing stamped louvres in such a top, the top was weakened. Furthermore, if the louvres were oriented radially outwardly from the center of the cover, the length of such louvres was limited because the open spaces provided between the louvres at the peripheral edge of the top are limited by agency requirements to no more than 1/2 inch in width. Therefore, the length of such louvres was limited, thereby limiting the overall size of the cover which could be provided by such arrangements. Further, by suspending a fan and fan motor directly from such stamped unitary tops, undesirable vibrations were set up in the cabinet thereby making such systems undesirable. It is therefore desired to provide a louvred cabinet top with a maximum total open louvred area in order to minimize resistance to air flow. It is also desired to provide such a structure which is dimensionally stable.
It is also desired to provide a unitary louvred top for an air conditioner condenser unit which is strong, is not subject to undue vibration and has a minimum resistance to air flow.